NEW YORK (Reuters Health) - Despite a commonly-held belief among many doctors who treat lupus patients, headaches -- particularly migraines -- are not a manifestation of that disease and should be treated as a separate problem, report researchers in Greece.

Previous studies that found migraines to be more common in patients with systemic lupus erythematosus (SLE) may have suffered from methodological errors, said senior author Dr. Dimos Mitsikostas from Athens Naval Hospital, and have led doctors to dismiss headaches as a neurological symptom of lupus.

Instead of being part of the disease, however, headaches may result from the stress of having the disease.

"In SLE, headaches may be associated with poor quality of life and bad mood. If an SLE patient reports headaches, please see if he or she is happy and if there is any other reason to cause secondary headaches and treat them not as an SLE feature, but like a separate disorder," Mitsikostas told Reuters Health in an email.

Although various studies of the headache question have produced conflicting results, the American College of Rheumatology includes headaches and migraine as part of the spectrum of lupus symptoms.

In a previous analysis, Mitsikostas and colleagues found no significant link between migraines and lupus. To clarify the association (or lack thereof), they performed the current study, in which lupus patients, healthy controls and multiple sclerosis (MS) patients all kept headache diaries for a year.

Like lupus, MS is a disease in which the body's own immune system attacks its nervous system, so Mitsikostas' group included 48 MS patients for comparison. The healthy controls in the study were matched by age and gender with the lupus patients to form 72 pairs.

All participants had similar headache frequencies in the year before the study period, except the lupus patients, who had a significantly higher number of tension-type headaches, the researchers report in the journal Headache.

Results were similar during the year of headache diaries: the three groups suffered comparable numbers of headaches, but chronic tension-type headache continued to occur more often in the lupus patients.

Migraine attacks were less severe and tended to be of shorter duration in lupus patients, whereas the severity of the chronic tension-type headaches was milder among lupus patients than among controls (but similar between lupus and MS patients).

Among both lupus and MS patients, the presence and type of headache could not be related to any other detectable manifestation of the disease, flare-up or cumulative damage.

Lupus patients had higher levels of anxiety and lower quality of life compared to controls and MS patients, and depression status was worse in lupus and MS patients than in controls. None of these features, however, coincided with the presence of headache.

"Although there are always missed points and issues for further evaluation, we feel that this study may be the last one in a long clinical research (path), starting 15 years ago," Mitsikostas concluded. "Yet, no pathophysiological links between SLE and migraine" could be found along the way, he wrote.

Somewhere between 322,000 and one million Americans are believed to have lupus, nine out of 10 of them women, according to the U.S. Centers for Disease Control and Prevention. The disease is difficult to diagnose and there is no cure. Although some symptoms are treatable, approximately one third of deaths among lupus patients occur before age 45.